Boring-tool.



PATENTED NOV. 21, 1905 P. THOMAS. BORING TOOL.

' APPLICATION FILED SEPT.27, 1904.

UNITED STATES PATENT OFFICE.

PHILIP THOMAS, OF NEW YORK, N. Y., ASSIGNOR TO HENRY R. WORTH- INGTON, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

BORING-TOOL.

Specification of Letters Patent.

Patented Nov. 21, 1905.

Application filed September 27, 1904. Serial No. 226,159.

To aZZ whom it may concern:

Be it known that I, PHILIP THOMAS, a citizen of the United States, residing at the borough of Brooklyn, city of New York, county of Kings, and State of New York, have invented certain new and useful Improvements in Boring-Tools, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

This invention relates to an improved boring-tool, the object being to provide a simple, strong, and efficient tool by which a hole of one size may be bored and the outer end of this hole enlarged to any desired depth, and

which shall provide for convenient grinding.

of the larger and smaller portions of the tool until the tool is used up.

As a full understanding of the invention can best be given by an illustration and description of a boring-tool embodying the same, such a description will now be given in connection with the accompanying drawings,

forming a part of this specification, and the features forming the invention will then be specifically pointed out in the claims.

In the drawings, Figure 1 is a side view of a drill embodying the invention in its complete and preferred form. Figs. 2 and 3 are crosssections on lines 2 and 3 of Fig. 1 looking in the direction of the arrows.

Referring to said drawings, A is the shank, and B the larger cutting portion, and O the smaller cutting portion of the tool. The smallerportion O is made of any desired length and is of the usual twist form, having the spiral raised portions (0 and grooves Z), the raised portions to having the usual edges 1 1. In the larger portion B of the tool the raised portions (4 and grooves b and the edges 1, the successive portions of which form cutting edges at the point of the tool as the tool is ground, are continued throughout the entire length of that part of the tool which is to be used by successive grindings. The cutting of the larger portion of the hole is provided by increasing the height of a portion of the parts a on the side next the grooves b to form the raised portions 0, having the spiral edges 2, successive portions of which form cutting edges at their ends for the larger bore as the larger portion of the tool is ground back, and which also extend the full length of that portion of the tool. At the base of the raised portions c'on the side at which the edges 2 are formed are preferably provided the small spiral grooves 3, parallel with the edges 1 2, which grooves aid in securing the proper clearance and oiling of the larger portion of the tool.

It will be seen that this boring-tool may readily be formed from asingle piece of metal, that both the larger and smaller portions may conveniently be ground until the tool is used up, and that there is no danger of injury to the edges 1 in grinding back the larger portion of the tool.

The edges 1 2 are shown as parallel, and this is preferable for grinding and machining; but the invention, considered broadly, includes tools in which these edges are not parallel.

It will be understood that the invention is not limited to a tool having two raised portions and grooves, but that this number may be varied and that the invention is not limited to the exact form of the tool shown.

lVhat I claim is- 1. A boring-tool formed of a single piece and having cutting portions of different diameters with the edges of the portion of smaller diameter extending through the portion of larger diameter.

2. A boring-tool formed of a single piece and having cutting portions of different diameters with the edges of the portion of smaller diameter extending through the portion of larger diameter and parallel with the edges of the latter.

3. A boring-tool formed of a single piece and having the smaller portion O with spiral grooves Z; and spiral edges 1 and larger portion B through which the grooves b and edges 1 extend andwhich larger portion is provided with raised portions 0 having edges 2.

4. A boring-tool having the smaller portion O with spiral grooves b and spiral edges 1 and larger portion B through which the grooves Z) and edges 1 extend and which larger portion is provided with raised portions 0 having edges 2 and clearance-grooves 3.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

PHILIP THOMAS. 

